首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 140 毫秒
1.
1. Collagen characteristics were compared in the tibiotarsus and humerus from 103 females and 38 males aged 68 to 72 weeks from the G6 generation of lines of laying hen selected for resistance or susceptibility to osteoporosis (high and low bone index (BI) lines). 2. Selection over the latest generation resulted in further divergence in the breaking strengths of humerus (from 12.3 to 21.8%) and tibia (from 22.3 to 37.3%) in hens. Males also showed line differences in bone strengths. 3. Plasma pyridinoline concentration was higher in hens in the low BI line, suggesting a greater rate of bone resorption in this line. 4. There were few differences between the lines in collagen and calcium concentrations in humerus and tibiotarsus cortical bone. 5. There were no differences between the lines in either sex in reduced immature collagen cross-link content of humerus or tibiotarsus. 6. Mature collagen cross-link content was higher in the high BI line in the male humerus but this effect was not apparent in the male tibiotarsus nor in either bone in the females. 7. Pyrrolic cross-link contents were higher in the high BI line in the female humerus and tibiotarsus and in the male tibiotarsus. 8. Over both lines combined, there were positive correlations between humeral and tibiotarsal pyrrole contents and strengths in females and between tibiotarsal pyrrole content and strength in males. 9. It is concluded that an increase in cross-linking, particularly pyrrolic cross-linking, in the collagen matrix contributes in part to the improvement in bone strength in the high BI line.  相似文献   

2.
Objective— (1) To evaluate resistance to axial extraction of 3 pin designs in avian humerus and tibiotarsus; (2) to assess the effect of pin location within the bone on holding power; and (3) to assess the influence of thread pitch on holding power. Study Design— Resistance of pins to axial extraction was measured immediately after insertion. Animals— Adult common buzzards (Buteo buteo; n=9). Methods— Different pin designs (1 smooth; 2 threaded pins, differing in pitch) were inserted into the proximal and distal metaphysis and the proximal, middle, and distal diaphysis of the humerus and tibiotarsus. Maximum force required for axial extraction of pins was recorded. Results— Smooth pins had the lowest extraction force (P<.05). Pins inserted into the diaphysis (proximal, middle and distal) of the humerus and the distal metaphysis of the tibiotarsus had a greater pullout strength than pins in other locations. Pins with a smaller pitch inserted into the proximal diaphysis and distal metaphysis of the humerus, and the proximal metaphysis of the tibiotarsus had significantly greater holding power than pins with a larger pitch (P<.05). Conclusions— Pins inserted into the diaphysis of humerus and the distal metaphysis of the tibiotarsus are better at resisting extraction. Pins with a smaller pitch possess greater holding power than pins with a larger pitch in avian humerus and tibiotarsus. Clinical Relevance— Consideration should be given to pin location and thread pitch, when choosing external skeletal fixation to repair an avian humeral or tibiotarsal fracture.  相似文献   

3.
1. As a baseline study of the nature and incidence of keel deformities in laying hens, keel condition was examined in three different strains of hen from a total of 4 different caged environments (two commercial farms and two experimental farms). Incidence of keel deformity on farms in end of lay hens ranged from 2.6 to 16.7%. Only 0.8% of younger 15-week-old pullets had deformed keels. 2. Incidence of keel deformities was unchanged in 100 birds sampled from a free-range system compared to conventional caged siblings at the same farm. 3. Keel condition was also examined in 5 selected generations of a study involving the use of a body-weight-restricted selection index for skeletal improvement. Divergent selection for skeletal characteristics decreased incidence of keel deformity and improved radiographic density (RD) in high bone index (BI) hens compared to low BI hens in all selected generations. Male high BI keels were also improved compared to low BI. Shear strength measured in normal keels in generation 6 (G6) of the genetic study was improved in high BI hens compared to low BI hens. For all hens in the genetic study, those with normal keels had stronger tibiotarsus and humerus breaking strengths than hens with deformed keels. 4. Histopathology of keels representative of different deformities showed the presence of fracture callus material and new bone in all cases. This establishes that deformities are a result of trauma and are not developmental in origin. 5. Ash contents of keels, tibiae and humeri showed no differences between hens with normal and deformed keels. There were no differences in indicators of collagen cross-linkage in other bones between hens with normal keels and those with deformed keels. 6. It is concluded that lack of bone mass is the underlying cause of keel fracture and deformity in laying hens, rather than qualitative changes in bone, and that genetic selection can improve keel quality and prevent deformity.  相似文献   

4.
The effects of body size and cage profile on the shear strength of bones from caged layers aged 72 weeks were studied. Bones tested included the radius, ulna, humerus, femur, and tibiotarsus. The ultimate shear force of the femur, tibia, and humerus all increased as body size increased (P less than 0.01). The wing bones of birds housed in high profile cages had higher shear breaking loads than birds housed in low profile cages. The ultimate shear stresses of the bones were not affected by body size or cage profile. The radius had the highest shear stress (29.2 MPa), followed in descending order by the ulna (19.1 MPa), tibiotarsus, humerus (11.4 MPa) and femur (11.3 MPa).  相似文献   

5.
The right humerus was removed from 30 20-week-old male turkey poults for humerus strength analysis using dual-energy x-ray absorptiometry and humerus-breaking strength. Specimens were cleaned and dried before scanning. To determine the most precise and accurate protocol of bone densitometry analysis for avian long bones, we scanned each specimen using five different techniques, all aimed to simulate soft-tissue thickness. Correlation coefficients and linear regression equations between 1) bone mineral content and humerus ash, and 2) bone mineral density and humerus-breaking strength were estimated with each technique and compared. The coefficient of variation values for precision ranged from 0.40% to 1.69% for bone mineral content and from 0% to 4.19% for bone mineral density. The accuracy was determined by comparing the bone mineral content of each humerus with the corresponding ash weight; the correlation coefficients between the two parameters were highly significant (range 0.949-0.963; P < or = 0.01). Significant correlations were also observed between humerus-breaking strength and bone density measurements (range 0.762-0.785; P < or = 0.01). Linear regression coefficients relating both parameters considered were also highly significant. We concluded that dual-energy x-ray absorptiometry is an accurate and precise method with which to determine ex vivo bone mineral content and strength in turkey bones. Further investigations are requested for field applications of this method to study factors affecting bone physiology and strength.  相似文献   

6.
1. Tibia and humerus breaking strength of Lohmann Silver hybrids kept in conventional cages, furnished cages and an aviary with outdoor run were examined in two production cycles. Each trial lasted a full laying period; feeding, management and healthcare were identical for all hens. In both trials bone strength was investigated at the end of laying months 6, 9 and 14. 2. The objective was to determine if bone strength increases when hens are kept in alternative housing systems, especially in furnished cages, and whether hen age affects bone stability. 3. The results indicated that housing system influenced bone breaking strength, which was consistently higher for hens in the aviary compared to hens in conventional and furnished cages. Furthermore, humerus breaking strength was higher for hens in furnished cages compared to conventional cages. No significant difference regarding tibia breaking strength was found between conventional and furnished cages. 4. Our results showed that lack of exercise contributed to the problem of weak bones more than did calcium depletion from eggshell formation. 5. Tibia breaking strength increased during the last third of the production cycle, whereas humerus breaking strength remained unaffected by hen age. 6. Genetic group affected only tibial bone breaking strength, which was lower overall in genetic group A than in group B, which in turn was lower than group C. 7. The increased bone strength in the aviary and in the furnished cages probably reduced the incidence of recently broken bones in these systems compared to the conventional cages. This increase in bone strength can be regarded as an improvement in welfare. Furnished cages, like the aviary system, might be considered an alternative housing system for laying hens, because both resulted in enhanced bone strength.  相似文献   

7.
Surgical repair of a fractured tibiotarsus in a scarlet macaw (Ara macao) is described. The forces imposed on the fracture site are discussed and the unique features of avian bone emphasised. Advantages of external skeletal fixation and specific details of the frame construction are highlighted.  相似文献   

8.
1. This investigation was carried out to study the influence of early quantitative food restriction (40% of ad libitum intake from 7 to 14 d of age) and environmental rearing temperature (thermoneutral, cold and hot) on long bone (tibia, femur and humerus) development in broiler chickens. 2. Tibia, femur and humerus were obtained at the ages of 14, 21, 28, 35 and 42 d, and the variables studied were: length and width (mm, expressed as absolute values), bone breaking strength (kgf) and bone weight/bone length index (BW/BL, mg/mm). 3. All bone variables increased with bird age. Food restriction reduced bone length and width but did not affect bone weight. High environmental rearing temperature reduced bone length and width at 42 d of age. Bone strength was not affected by environmental temperature but the calculated BW/BL index was reduced by heat exposure. 4. The findings suggest that food restriction and high environmental rearing temperature reduce long bone growth; bone breaking strength was affected by bird age but not by food restriction nor rearing ambient temperature.  相似文献   

9.
Two experiments were conducted to study the effect of standardized ileal digestible (SID) leucine and valine levels on tibiotarsus bone characteristics and the incidence of tibial dyschondroplasia of broilers from day 1 to 21 (Experiment I) and day 21 to 42 post‐hatch (Experiment II). Each experimental phase was evaluated independently. In both experiments, a total of 1,500 one‐day‐old Cobb 500 male broiler chickens were distributed in a completely randomized design 5 × 5 factorial arrangement for a total of 25 treatments. The SID leucine and valine levels were ranged from 10.0 to 19.6 g/kg, and 6.0 to 12.0 g/kg from day 1 to 21 post‐hatch, respectively, while day 21 to 42 post‐hatch ranged from 10.0 to 18.0 g leucine/kg, and 5.2 to 11.2 g valine/kg. Serum calcium and phosphorus, bone concentrations of calcium, phosphorus and ash, diameter and Seedor index of the tibiotarsus were not affected (p > .05) by the treatments at 21 or 42 days of age. There was an interaction (p ≤.06) between the SID levels of leucine and valine on tibiotarsus breaking strength at 21 days, but not at 42 days of age (p > .05). Tibiotarsus breaking strength was maximized in broilers from day 1 to 21 with the dietary levels of leucine and valine at 14.2 and 9.0 g/kg respectively. Dietary leucine levels reduced linearly (p < .05) the hypertrophic zone of tibiotarsus cartilage at 21 days of age. Therefore, leucine and valine supplementation interact positively on bone strength of broilers from day 1 to 21 post‐hatch. Leucine can be a useful amino acid for reducing the hypertrophic cartilage zone in broilers from day 1 to 21, but not from day 21 to 42 post‐hatch.  相似文献   

10.
OBJECTIVE: To assess whether site-related changes in biochemical composition are present in the cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis. SAMPLE POPULATION: Right metacarpophalangeal joints from 59 mature warmblood horses. PROCEDURE: Biochemical data (cross-link, amino acid, DNA, and ash contents; denatured collagen and glycosaminoglycan [GAG] concentrations; bone mineral density; and mineral composition) were obtained from 2 differently loaded sites of phalanx I cartilage and subchondral and trabecular bone samples; data were compared with previously published values from nonosteoarthritic equine joints. RESULTS: Compared with findings in nonosteoarthritic joints, GAG concentration was lower in cartilage from osteoarthritic joints and there was a loss of site differences in cellularity and lysylpyridinoline (LP) cross-link content. In subchondral bone, LP cross-link content was decreased overall and there was a loss of site differences in osteoarthritic joints; ash content was higher in the osteoarthritic joints. Hydroxyproline content in trabecular bone from osteoarthritic joints was greater than that in nonosteoarthritic trabecular bone. In all 3 layers and at both sites, the linear increase of the pentosidine cross-link content with age had diminished or was not apparent in the horses with osteoarthritic joints. CONCLUSIONS AND CLINICAL RELEVANCE: In equine metacarpophalangeal joints with early osteoarthritis, distinct biochemical changes were detected in the cartilage and subchondral and trabecular bone. The dissimilarity in response of the different tissues and differences between the sites that are affected may be related to differences in biomechanical loading and transmission and dissipation of force.  相似文献   

11.
REASONS FOR PERFORMING STUDY: A detailed and comprehensive insight into the normal maturation process of the different tissues that make up functional units of the locomotor system such as joints is necessary to understand the influence of early training on musculoskeletal tissues. OBJECTIVES: To study simultaneously the maturation process in the entire composite structure that makes up the bearing surface of a joint (cartilage, subchondral and trabecular bone) in terms of biochemical changes in the tissues of juvenile horses at 2 differently loaded sites of the metacarpophalangeal joint, compared to a group of mature horses. HYPOTHESIS: In all the structures described above developmental changes may follow a different timescale. METHODS: Age-related changes in biochemical characteristics of the collagen part of the extracellular matrix (hydroxylysine, hydroxyproline, hydroxypyridinum crosslinks) of articular cartilage and of the underlying subchondral and trabecular bone were determined in a group of juvenile horses (n = 13) (Group 1, age 6 months-4 years) and compared to a group of mature horses (n = 30) (Group 2, >4 years). In both bony layers, bone mineral density, ash content and levels of individual minerals were determined. RESULTS: In cartilage, subchondral bone and trabecular bone, virtually all collagen parameters in juvenile horses were already at a similar (stable) level as in mature horses. In both bony layers, bone mineral density, ash- and calcium content were also stable in the mature horses, but continued to increase in the juvenile group. For magnesium there was a decrease in the juvenile animals, followed by a steady state in the mature horses. CONCLUSIONS: In horses age 6 months-4 years, the collagen network of all 3 layers within the joint has already attained a mature biochemical composition, but the mineral composition of both subchondral and trabecular bone continues to develop until approximately age 4 years. POTENTIAL RELEVANCE: The disparity in maturation of the various extracellular matrix components of a joint can be assumed to have consequences for the capacity to sustain load and should hence be taken into account when training or racing young animals.  相似文献   

12.
Skeletal development in the meat-type chicken   总被引：1，自引：1，他引：0  
1. This study ascertained how bone of modern meat-type chickens develops under typical commercial conditions and compares development with that in genetic precursor stock. 2. A modern fast-growing selected strain and a slower-growing control strain were used. Birds were weighed weekly. A random sample was taken from each population at a range of ages up to 39 d. 3. A tibiotarsus from each bird was X-rayed and its dimensions and estimated resistance to bending were determined. Cortical bone samples were ashed to measure total mineral, calcium and phosphorus content. Cortical samples were also taken for porosity assessment. 4. As expected, the selected strain grew faster and heavier than the control strain. Despite this, both strains demonstrated similar periods of rapid bone formation (days 4 to 18) and mineralisation (days 4 to 11), and achieved similar estimates of resistance to bending. 5. However, cortical bone of the selected strain was less well mineralised and more porous than that of the control strain and showed a significant increase in the molar Ca:P ratios above the expected range of values during the first 2 to 3 weeks of life. 6. Despite production of bones with the correct dimensions for load support, the relatively poor density and mineral content of bone in the selected strain is likely to reduce effective breaking strength of the tibiotarsus. Possible reasons may be either inadequate dietary supply of Ca and P or impaired utilisation of the minerals due to a rapid growth rate or genetic factors.  相似文献   

13.
1. The aim of the present study was to determine the influence of large (54 or 60) and small (36 or 40) group sizes and tiers of the small group housing system “Eurovent German” on tibia and humerus bone breaking strength, keel bone status, plumage condition and egg quality for two commercial layer lines, Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB), at the same stocking density (890 or 830 cm2/bird).

2. In 4 consecutive trials, 4752 hens were recorded for keel bone status. Evaluation of plumage condition was made for 1440 hens and bone breaking strength was recorded for 1200 hens. A total of 4962 eggs were analysed for internal and external egg quality traits. Analyses involved 30 small group compartments per trial.

3. The layer line had a much more pronounced influence on humerus breaking strength than on tibia breaking strength.

4. Plumage condition, particularly on the neck, was positively correlated with humerus breaking strength in both layer lines.

5. An average of 34% of LB and 23% of LSL hens showed keel bone deformities, with higher proportions of slight deformities.

6. Slight keel bone deformities, rather than moderate to severe, increased significantly during the laying period.

7. Stocking density had no influence on bone breaking strength, keel bone status and egg quality traits.

8. LB layers had a 1.4-fold higher humerus, but only a 1.06-fold higher tibia breaking strength compared to LSL layers.

9. Tibia breaking strength was significantly affected by the interaction of group size and layer line. LSL layers in small groups had lower tibia breaking strengths than those of the large groups.  相似文献   


14.
The responses of skeletal health and blood calcium (Ca) and phosphorus (P) status to different dietary calcium and available P (avP) contents were examined in 2-week-old chickens. High avP content resulted in more inorganic P (P(i)) and less ionised Ca (Ca(2+)) in the blood. Birds on low Ca and high avP diets showed a higher incidence of tibial dyschondroplasia and hypocalcaemic rickets and were therefore assumed to be hypocalcaemic. However the molar Ca:P ratio in bone was closer to the expected 1.67:1 in diets high in avP. No significant dietary mineral content effect was found on bone mineral content, or breaking strength, within the range of diets used. Results suggest that variations in molar Ca:P ratios in bone have little effect on mechanical competence, and that diets for this strain should be higher in Ca, and could be lower in avP, than current recommendations.  相似文献   

15.
Bioactive substances including taurine, l-carnitine, polyunsaturated fatty acids, flavonoids and antioxidants were shown to influence the perinatal development of a majority of mammalian systems, nervous, gastrointestinal, immune, etc. A blend of bioactive substances and plants was composed to supplement sow feedstuff, and our study aimed to examine the bone parameters in their offspring. Control sows were fed with a standard diet alone (n = 6). The sows from the supplemented group (n = 6) received the supplementation from the gestation day 80 until the end of lactation. From each sow two piglets were sacrificed, one at 7 d and the second at 28 d of life. The femur and humerus were isolated, bone mineral density and mineral content were determined using dual energy X-ray absorptiometry. Bone maximum strength and elastic force were determined by a three-point bending test. No differences in the body weight were found. At day 7, the bones of piglets from the supplemented group were characterized by higher weight, physical parameters and bone mineral content as compared to control, no difference in length and bone mineral density was observed. At day 28, no differences in humerus parameters were found as well as in femur mineral density and mineral content. However, in relation to the body weight, the weight and physical parameters of femur were higher in the supplemented group as compared to control. In conclusion, the supplementation of sow diet with bioactive substances influenced the development of bones in their offspring.  相似文献   

16.
This study examined the effect of age on bone breaking strength and the prevalence of broken bones in hens kept in a perchery egg laying system. During the first 6 weeks of lay, bone strength increased by about 25%. The prevalence of broken bones which had repaired increased from 0% at 19 weeks of age to 23% at 72 weeks. Most of this increase occurred during the last half of lay and during this period the humerus became slightly more brittle. The exact reason for the increase in broken bones was not revealed, but because they occurred largely in the keel and furculum they were thought to be due to flight and landing accidents.  相似文献   

17.
It is known that female birds increase medullary mineral stores in long bones shortly before egg laying. Here, we present results from two groups of budgerigars, in both of which females had significantly higher bone mineral contents and densities, as measured by peripheral quantitative computed tomography of the tibiotarsus, during a reproductively dormant period. The results could indicate that female birds can accumulate mineral stores outside of the breeding season.  相似文献   

18.
The influence of high dietary intakes of protein and energy on bone development was described and the accuracy of radiographic photometry as an estimator of bone mineral content was determined. There were higher (P<.10) values for breaking strength and cortical area, and lower (P<.10) percentages of calcium and total mineral content in the bones of ponies on high planes of nutrition. These ponies developed at a faster rate than the normally fed ponies, suggesting that during accelerated growth bone mineral deposition may be reduced. Thus, high intakes of energy and protein appeared to increase the rate of skeletal growth while decreasing deposition of mineral into bone. These conditions may be related to bone failure from high compressive loads.Radiographic photometry was found to be an adequate predictor of bone mineral, calcium and phosphorus content in live ponies. However, care must be used in obtaining the radiographs to ensure the accurate estimation of mineral status.  相似文献   

19.
The main objectives of the study were to provide an accurate assessment of current levels of old breaks in end-of-lay hens housed in a variety of system designs and identify the important risk factors. Sixty-seven flocks housed in eight broad subcategories were assessed at the end of the production period. Within each flock, the presence of keel fractures was determined and the tibia, humerus and keel bones dissected for measurement of breaking strength. For each house, variations in internal design and perching provision were categorised and the effective heights of the differing structures recorded. All systems were associated with alarmingly high levels of keel damage although variation in mean prevalence between systems was evident with flocks housed in furnished cages having the lowest prevalence (36 per cent) despite also having significantly weaker bones and flocks housed in all systems equipped with multilevel perches showing the highest levels of damage (over 80 per cent) and the highest severity scores.  相似文献   

20.
OBJECTIVE: To investigate the effectiveness of intramedullary xenograft cortical bone pins compared with stainless steel Kirschner wire for the repair of a standardized avian humeral fracture. STUDY DESIGN: Prospective randomized study. SAMPLE POPULATION: Thirty mature pigeons (Columba livia). METHODS: Birds were randomly assigned to 3 groups. Transverse mid-diaphyseal humeral fractures were created in 1 humerus in each bird. Fractures were stabilized with intramedullary ostrich or canine xenograft cortical bone pins or Kirschner wire. Radiographic, histological, and biomechanical assessments were used to compare fracture healing 6 weeks after fracture stabilization. The contralateral humerus of each bird was used as a control. RESULTS: All fractures healed regardless of intramedullary pin type. There were no statistically significant biomechanical differences among groups or within groups. Xenograft cortical bone pins induced a mononuclear inflammatory reaction that did not impair bone healing. Bones stabilized with intramedullary cortical bone pins had more periosteal callus and inflammation at the fracture site than bones stabilized with stainless steel Kirschner wires. CONCLUSIONS: Intramedullary xenograft cortical bone pins, derived from mammalian or avian sources, appear to represent an alternative for the repair of avian humeral fractures. CLINICAL RELEVANCE: Intramedullary xenograft cortical bone pins are biodegradable and may reduce the need for additional surgery to remove implants after fracture healing.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号